One theory behind social networking postulates that if person A wishes to meet person B, s/he can leverage friends and acquaintances to achieve that result. In the course of conducting their everyday affairs (whether personal or business), people generally access their networks of contacts for referrals, information and/or advice on a variety of matters, for example                When choosing a physician        When seeking a new employee or employer        When investigating new investment opportunities.        
In examples such as these, an individual's decisions can be made more efficient if s/he has access to the advice of trusted associates and friends. However, it is often the case that an individual will find that s/he does not know anyone with the information s/he needs at a specific place and time. In such a situation, the individual may try going out an extra degree within his or her own “human networks” by asking a contact to provide the name of a contact who may have the needed information. This presents a quandary for the person asked for a referral—namely, whether or not to reveal his or her contacts to the requester. By making such revelations, the “connector” may compromise his or her network or expose one or more of his or her contacts to unwanted solicitations. By not making the referral, however, the connector may risk his or her association with the person seeking the referral. Whether or not to make the referral often depends upon the degree of trust that the connector has in the person seeking the referral and any past experiences in making such referrals to the target referee.
Even where the referral is ultimately made, there is no guarantee that the referee is going to be a suitable candidate for the original requestor's purpose. Thus, the requestor may be forced to track down a number of leads (many of which may be unsuitable) in the hope of finding a suitable target. This process is rather inefficient, usually because a) the requestor does not have enough information about the contacts of his or her contacts in order to determine which contacts to approach for referrals, and/or b) the requestor has failed to properly elucidate his or her requirements and/or because the requestor was not provided with sufficient information regarding the potential target to be able to eliminate him or her from further consideration. In other words, the profiles of the desired target and the resulting candidates were not sufficiently developed to meaningfully assist in the selection process.
Despite their inefficiencies, human networks are central to most, if not all, value-creating activities and operate at multiple levels, including personal networks (the personal and professional contacts each of us has), organizational networks (links within and between organizations), and associations and interest groups (people attracted by common values, interests, and goals). Today, many individuals may also be regarded as existing online community members, members of organizational networks (independent consultants, alliances, partnerships, consortiums, associations) or employees of small to large companies. They engage in human development, organizational learning, training, management, brokering, marketing, sales, trade, research, and consulting activities, all of which depend, to some degree, on inter-human networks. Such individuals generally understand the value of computer networks as tools for sharing information, but presently these individuals have only limited access to tools that can give them an edge (e.g., a competitive advantage) to make better human network connections on the Internet. However, even with the advantages provided by the Internet, opportunity is still limited by the reach of an individual's personal network.
Others have recognized some of these deficiencies and have proposed partial solutions. For example, some prior schemes for leveraging human network characteristics show the benefit of using automated means to assist in decision-making processes regarding the use of such networks. However, these schemes do not assist in the forming of relationships or introductions among members of disparate human networks nor do they provide for the brokering function discussed above, which is critical to the exchange of social capital among individuals. Other schemes include access control systems that generally allow only intended users to have access to information. Such systems may make use of encryption schemes, such as public/private key encryption schemes, or other access controls such as:                Simple access that is either open or closed.        Schemes wherein data or data areas are separated into public and private (or further) designations.        Schemes which use multiple access groups to which people and other groups are assigned.        Schemes involving role-based access control.        
In addition to access control schemes, other profiling systems do exist and are often used as adjuncts to e-commerce technologies to provide some limited contact book updating capabilities.